First-choice midfielders James McCarthy and Glenn Whelan have today been ruled out of tomorrow's European qualifier with Scotland in Glasgow.

The pair were this morning sent back to Everton and Stoke City respectively after failing to overcome their injuries.

McCarthy has been dogged by hamstring trouble since Sunday and did not train in Malahide this week.

And while Whelan did train, he has not played since fracturing his leg against Germany in Gelsenkirchen four weeks ago.

The rest of the squad trained in Malahide this morning ahead of their afternoon flight to Glasgow for tomorrow's Celtic Park clash.

Darron Gibson, Jeff Hendrick, Stephen Quinn and David Meyler are O'Neill's options in the engine room.

O'Neill is concerned about Gibson's lack of sharpness having struggled to get back into the Everton team since his cruciate injury. But he did play 75 minutes off the bench against Sunderland last Sunday.